Biopsy forceps, especially those used in endoscopic procedures, must be small, readily manipulable, very sharp, and able reliably to retain the excised tissue while the forceps are being withdrawn.
Forceps for this purpose are well-known, although they generally fulfill their objectives to less than optimum satisfaction. One of their shortcomings is their cost. These forceps are very small, and are made to near-watchmaker precision. Forming their general shape is a simple task, but sharpening their edge, and providing sharp jaw edges which precisely abut one another is more difficult.
In Cox U.S. Pat. No. 5,097,728, issued Mar. 24, 1992, there is shown a method to make a small biopsy cup with a sharp edge. This edge is formed on a flat plate, and the plate is folded to form a cup in which the excised tissue is received. This device enjoys substantial utility, but has limitations which this instant invention proposes to overcome.
Another disadvantage of prior art biopsy forceps is the inherent limitation on how far their jaws can be opened. Because they are cup-shaped, their jaw opening is quite limited in order that a cut can be completed. If the cups are filled, then the jaws could not be fully closed to complete the cut. Also, if the jaws are opened after the cut is made, the specimen may be lost. The surgeon is unable to view the sample he has taken without assuming this risk. Too often, the closed forceps are withdrawn and when opened are found to be empty.
In its preferred embodiment this invention includes stabilizing means to stabilize the tissue while it is being severed, and has an open bottom so that the jaws cannot be overfilled. As a consequence, a very shallow cut can be made, which profoundly reduces the risk of perforation, and the jaws can be opened while still in the endoscopic system so that their content can be viewed through the endoscope without requiring removal of the forceps. In fact, it is even possible to take multiple specimens, because the stabilizing means tend to retain excised tissue even when the jaws are opened.